Ni Chang, Zhang Ming, Zhu Yu, Hu Chuxiong, Ding Siqi, Jia Zhe
Appl Opt. 2017 May 1;56(13):3895-3899. doi: 10.1364/AO.56.003895.
In a sinusoidal phase-modulating interferometer, sinusoidal modulation of the phase of the laser or the reference wave is necessary. However, modulation of the phase also involves an intensity modulation of the light, which leads to a measurement error if conventional signal processing is used. In addition, the error of modulation depth and the phase delay of demodulation also increase the measurement error. A novel signal processing, with ellipse fitting and a correction method, is proposed. Numerical simulation results and experimental results prove that the novel signal processing can compensate for the measurement error caused by the intensity modulation, the error of modulation depth, and the phase delay of demodulation.
在正弦相位调制干涉仪中，对激光或参考波的相位进行正弦调制是必要的。然而，相位调制也涉及光的强度调制，如果使用传统的信号处理方法，这会导致测量误差。此外，调制深度误差和解调的相位延迟也会增加测量误差。本文提出了一种采用椭圆拟合和校正方法的新型信号处理方法。数值模拟结果和实验结果证明，该新型信号处理方法可以补偿由强度调制、调制深度误差和解调相位延迟引起的测量误差。
